DESCRIPTION (provided by candidate): The proposed research is designed to advance current thinking on children's evaluation and use of testimony. By assessing what factors influence children's willingness to believe the testimony of others, the current research proposal aims to shed light on the safeguards children of different ages may utilize to protect themselves from false, misleading or otherwise problematic information. Experiments 1 and 2 will examine the extent to which young children, aged 2-5, are able to monitor and use the truth of the assertions made by individual informants to gauge the reliability of subsequent testimony. Experiments 3 and 4 assess whether children not only monitor the truth of an individual's assertion but also whether assertions are appropriately justified or not. Children aged 3-4, 5-6 and 7-8 years as well as adults will be asked to accept or reject the novel claims of characters who differ in terms of whether their prior claims were (i) true or false and (ii) justified or unjustified. Given that the utility of testimony as a source of information likely depends on what kind of information is being evaluated, Experiments 1 and 3 focus on assertions provided in the context of object naming whereas Experiments 2 and 4 focus on assertions provided in discussion of object function. In Experiment 5, the conditions under which children spontaneously (i~ query the truth of an assertion or (ii) ask for an assertion to be justified will be examined. An assessment of children's abilities to evaluate other's testimony will provide a window into children's use of one of our most valuable information sources - other human agents.